1. Field of the Invention
The present invention relates an apparatus for forming a pair of disk-shaped metal blanks into grooved wheels.
2. Description of the Prior Art
It is well known in the art, such as, in a Japanese Utility Model Registration No. 876,591 (Utility Model Publication No. 30,040/1968) that a pair of rollers arranged on diametrically opposite sides of a disk-shaped metal blank are fed toward the blank for forming a grooved wheel. In such a conventional apparatus, it has been very difficult to control the feed speeds of the two rollers to be the same so that the two rollers have not effectively functioned. Accordingly, a blank has been formed into a grooved wheel by one of the rollers in one forming operation, while another blank has been formed by the other roller in another forming operation, whereby grooved wheels with uniform accuracy have not been obtained.
It is also well known in the Japanese Utility Model Registration No. 876,591 that two blanks are mounted on opposite ends of a spindle so as to be formed simultaneously. However, in such a conventional apparatus, two rollers for forming the two blanks are synchronously connected with each other so that it has been impossible to form two different blanks at the same time. Moreover, it has been very troublesome to exchange the roller.